This is a Smith & Wesson Revolver: Double Action known as the 500 chambered in 500 SW Magnum, model # 163504, UPC 022188635041
Model Series: 500
Gun Type: Revolver: Double Action
Caliber: 500 SW Magnum
Action: Double Action
Capacity: 5
Finish: Satin Stainless Steel
Stock: Hogue Sorbothane Recoil Absorbing Grip
Sights: Front: Red Ramp Rear: Micrometer Click Blk Blade
Barrel Length: 4 (3 + 1 Compensator)
Overall Length: 10.25
Features: Removeable Inerchangeable Compensator:
